1. Field of the Invention
This invention relates to the use of S-allylcysteine as an antineoplastic agent. More specifically, it relates to a method of inhibiting the proliferation of certain malignant melanoma cells in a mammal by administering to the mammal the afore-indicated antineoplastic agent.
2. Related Art
Garlic products are believed to possess beneficial effects in maintaining good health such as providing resistance to infections, lowering cholesterol levels, detoxifying harmful substances, relieving stress, and enhancing the immune response. For thousands of years they have been part of folk medicine. Certain extract forms of garlic are antibacterial and antifungal, and others are antithrombotic.
Garlic and onion oils have previously been reported to inhibit carcinogenesis in several experimental animal models (S. Belman, Carcinogenesis, 1983, 14, 1063). More specifically, this study reported that garlic and onion oils inhibited the growth of DMBA (7, 12-dimethylbenzenanthracene)-induced or PMA (phorbol-myristate-acetate)-promoted skin papillomas in mice, as well as inhibiting the growth of DMBA-induced hamster buccal pouch carcinomas.
Organosulfur compounds (OSC) isolated from garlic extracts have also been shown to inhibit tumorigenesis induced by chemical carcinogens. For instance, Sumiyoshi et al., in Cancer Res., 1990, 50, 5084, reports that one water soluble OSC (S-allylcysteine) inhibits DMH (1,2-dimethylhydrazine)-induced nuclear aberration in mouse colon. OSC's are believed to stimulate the activity of GST, which is an enzyme known to be involved in the detoxification of many carcinogens. Therefore, increased GST activity may be responsible for the inhibition of tumorigenesis.
These findings, in part, support the conclusions from epidemiologic studies that consumption of fresh fruits and vegetables reduces cancer risk. However, in spite of the apparent chemopreventive effects of garlic extracts and OCS's, prior to the present invention, there was no suggestion that OCS's or its salts could inhibit the proliferation of carcinoma cells.